Automotive control systems and vehicle sensor systems are employed to sense various environmental and performance related operational conditions in and around the vehicle as well as for providing feedback data from the many actuators, controls and sensors of the vehicle. The operating conditions sensed, and/or the resultant output measurements produced by these sensors systems are usually confined to a predetermined or known operational range of measurement values when they are working properly. In addition, when these vehicle sensors are properly connected to their respective wiring harnesses, and these wiring harnesses are providing adequate continuity, the respective output measurements will also remain confined to within their predetermined or known operational ranges as seen by the vehicle electronics control module (ECM) or on-board vehicle computer.
Two such sensors that provide operating performance data to the ECM, are the individual wheel speed sensors of the automatic braking system (ABS), and the engine oxygen (O2) sensor monitoring the relative percentage of unused oxygen in the combustion process.
Conventional automotive diagnostic equipment has been designed to test some of these electrical system components as may be monitored by the ECM or vehicle computer. However, such diagnostic equipment may be rather expensive and may not be able to ascertain whether the sensor, the interconnection cable between the ECM and the sensor, or the ECM itself is at fault.
Current diagnostic systems may further tend to be inefficient in regard to using more peripheral test equipment than may be required. In addition, present automotive diagnostic systems may not provide system safety or failure prediction information valuable to the user or other such information necessary to diagnose and maintain continued system operations or to avoid an impending automotive sensor system failure.
For design, manufacturing, and applications reasons, the automotive diagnostic systems for diagnosing vehicle sensors and sensor systems discussed above are generally large, complex and/or expensive. Further, the use of these automotive diagnostic systems, supporting equipment and individual sensors also require more system set-up time, additional wiring and added complexity in support of the automotive diagnostic system. Such additional systems, supporting equipment and the associated interface wiring may increase the overall cost and complexity of the system.
Accordingly, to accommodate improved efficiency, lower cost, ease of use and system simplicity goals, there is a need for an automotive diagnostic system that incorporates sensor simulation and sensor failure detection and prediction functions as well as other associated system detection and diagnostic capabilities in an automotive diagnostic system.